The phrase "a formal separation" is correct and usable in written English.
It can be used in contexts discussing the official ending of a relationship, partnership, or organization.
Example: "The company announced a formal separation from its subsidiary to streamline operations."
Alternatives: "an official split" or "a structured division".
It is done by first declaring a formal separation.
The mayor's response was to announce that he and Ms. Hanover would pursue a formal separation.
Sollecito's lawyer, Giulia Bongiorno, is seeking a formal separation between her client's case and Knox's case.
Conservative Episcopalians in the United States are also making plans for a formal separation.
As a result, Citigroup has agreed to a formal separation of its research and banking units.
But it has little doubt that a formal separation from China by Taiwan could mean war.
China condemns the referendum as a step toward formal separation, and the United States has called it provocative and an unnecessary step that raises tension across the Taiwan Strait.
A second problem is the formal separation - through funding streams and organisational structures - of humanitarian activities into sectors (Pain and Levine 2012), which disconnects shelter and housing from other fields of action affecting the household (Crawford 2011).
In the year of their formal separation, Howe recorded a deed for the support of his wife.
With the Dreyfusards in the ascendant, the affair marked the start of a new phase in the history of the Third Republic, a phase in which a series of Radical-led governments pursued an anticlerical policy that culminated in the formal separation of church and state (1905).
The status of the town was changed by a later charter of Charles I by at once the formal separation from Portsmouth and the recognition of Southampton as a county, In the charter dated 27 June 1640 the formal title of the town became 'The Town and County of the Town of Southampton'.
